1. Field of Invention
The invention relates to a key module and, in particular, to a key module, which has an elastic element to construct a larger pressing surface.
2. Related Art
Everyday electronic devices, such as desktop computers, laptop computers, or PDAs (Personal Digital Assistants), usually include a number of keys for inputting specific functions. The keys are, for example, numeral keys, power keys, and reset keys.
FIG. 1 shows the structure of a conventional key. As shown in FIG. 1, the key 11 is disposed in a casing 12 of an electronic device. A key surface 111 of the key 11 is exposed from the casing 12, and the key surface 111 is protruding from a surface 121 of the casing 12. Since the key surface 111 is protruding from the surface 121, users can easily touch and press the key 11. However, the key 11 may be often unintentionally pressed. This is a very common annoyance. If the unintentionally pressed key is a specific key, such as the power key or the reset key, some irreversible events may occur. For example, the electronic device may be suddenly shut down or the configurations of the electronic device may be reset.
FIG. 2 shows a structure of another conventional key. As shown in FIG. 2, the key surface 111 of the key 11 and the surface 121 of the casing 12 are disposed at the same plane. In this case, the key surface 111 is lower, so that the events of unintentionally pressing the key 11 can be greatly reduced. However, the operation of the key 11 is much less convenient due to the fact that the area of the key surface 111 is smaller than the corresponding area of the human finger. Accordingly, the users have to use their fingertips or fingernails to poke the key surface 111 in order to properly press the key 11.
Therefore, it is an important subject of the invention to provide a key module, which can prevent unintentional depression events and make the intentional depression of the keys more convenient.